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Tone arm and Cartridge Wiring Help Needed!

M

MagnaZach

New Member
Audiokarma. After replacing everything else on my Magnavox Micromatic, I attempted to replace the cartridge and wiring harness. The original harness had 2 metal-jacketed wires…brown and grey. The jackets were used for grounds. I ordered a new harness and cartridge from V-M. I used the green and black wires from the new harness as grounds. I grounded the metal cartridge bracket with one and the negative left pin with the other. I re-used the tiny metal hooped wire from the old cart onto the new cart. I believe it just bridges the negatives together. I used the red wire for the right channel and the white wire for the left. I ran the new wires to the same contact points near the RCAs as the original harness. I have NO sound now from the record player!! I can touch the RCAs and get a nice buzz. I can plug my blue tooth adapter into the record inputs and get great sound so I’m fairly sure the problem is somewhere between the cartridge and harness. I checked all of my new connections and then shrink wrapped them for protection. I did test all wires from the pins on the cart to the contacts on the RCA with my ohmmeter and everything checked out. Can someone please let me know what to try next? I’ve included pictures of the old cartridge and original RCA contacts as well as the new cartridge and new RCA contacts.

BDCAA6E8-C53A-4A47-98C2-992732B9F1DB.png B1E658A8-EE8D-4E8D-9975-89E8661961CE.jpeg BD427D21-0F56-4E77-BB49-7F038C3AC661.jpeg 95342265-A27C-4DF1-BE83-D7B06375B535.jpeg 27B7D9E9-74FA-4339-89AE-8A753B111AA2.jpeg 85568C51-4DD0-4926-80BB-CDC6E5C7ABD7.png
 
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Just until you get it working, I wouldn't ground it to that plate and use all four lugs, not just the three.

Use your ohm meter after you have soldered everything into place. Your white and red wires look questionable going to the RCA jacks on the bottom of the turntable. Make sure they have good continuity and I would also thread them through their tiny holes (if you haven't already done so).
 
Thanks Cademan! I did go through and clean up my solder job and found the tiny holes on the jacks and fed the wires through them before soldering again. I still can’t get any sound. I ordered another wire harness and cartridge. I installed them and the same result. This unit did have decent sound from the turntable before I attempted the replace the cartridge and wire harness but they were old and frail so I opted to replace them. I don’t know what else to do!
 
Interesting. I would say to just make sure all wires are stripped properly so the copper wires are making good contact on all your connections.

Also in case you didn't know, the main RCA input jacks on the turntable itself, acts like a switch which opens contacts when the turntable is in "REJ" mode. This just stops all pops or tone arm noise when the record is being changed or rejected. Make sure that these contacts are closing properly when a record is being played.
 
5635FAE8-05F7-4917-8E7F-25863AAD88B1.jpeg 2EFF6CE3-0BF4-4186-9E6C-D092C6195E14.jpeg I had some time today to try and narrow down the issue. I bypassed the RCAs on the turn table and used jumpers to hook the cartridge directly to the RCA cables and I got a nice hum when I touched the needle. I think this narrows it down to the wires or the RCA jacks on the turntable. I tested the wires for continuity and they all checked out. Could the RCA jack assembly be bad? It looks like a fairly simple device so I’m not sure where it could fail but I don’t know what else it could be.
 
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